Radiator core for automobile cooling systems



Sept. 20;1932. w. w. MUIR 1,878,511

RADIATOR CORE FOR AUTOMOBILE COOLING SYSTEMS Filed April 27, 1929 Patented Sept. 20, 1932 -UNETE WELLINGTON W. MUIB, 0F LOCKPOBT, NEXV YORK, ASSIGN'OR TO; HARRISON 'RADIATOR CORPORATION, OF LOCKIPOET, NEW YORK, A CORPORATION OF NEW YORK RADIATOR CORE FOR AUTQMOBILE COOLING svsrnMs Application filed April 27,

Thisinvention relates to the cores of radiators for the cooling systems of internal com bustion engines or the like and has for its ticularly pointed out in the claims.

Referring to the accompanying drawing forming a part of this specification in whichlike numerals designate like parts in all the views,

Fig. 1 is a vertical sectional view of a portion of the radiator core made in accordance with this invention showing the method of assembling the separator strip within one of the core units;

Fig. 2 is a much enlarged diagrammatic illustration showing the construction of one of the water tubes;

Fig. 3 is an elevational view of a portion of the separator strip employed with the core construction in accordance with this invention;

Fig. 4 is a detail perspective view of the separator shown in Fig. 3;

Fig. 5 is a detail elevational view of a portion of the water tubes of the radiator core ter understood it is said that heretofore radiator core constructions have been such that either vertical or substantially horizontal water tubes have been formed which permit a passage of water therethrough with insufficient cooling thereof under some conditions.

1929. Serial No. 358,740.

a too direct. passage for the cooling fluid through the radiator whereby insuflicient time" is given to the fluid for complete cooling there of, and other factorswhich will be readil observed and understood by those'skilled in the art. The purpose of this invention is to provide a construction which is somewhat similar to prior constructions in that the core units are made from extremely thin metal strips which are preformed by crimping into shapes which will readily -fit one another or which will fit separator strips provided therefor, all to the end that the passage of cooling fluid through the radiator core will be broken, interrupted, or otherwise afiected so that a transfer of more heat to the atmosphere is accomplished because of the prolongation of the passage of'the fluid through the tubes of the core. A still further object of the invention is to provide a construction offering less resistance but more turbulence to'the air'passing through the core for absorbing the heat given off from the cooling fluid.

This invention is particularly applicable to radiators having substantially hexagonally formed air cells in its core, it being understood that other forms maybe readily devised which will still fall within the limits of this invention. The actual formation of these cells should be described so that the in-' vention may be the better understood and therefore the following is directed to a disclosure of such construction. p Y

Extremely thin sheets of soft metal, having high heat conductivity and such for example as copperor brass, are formed into narrow strips of about 2 to 4 inches width. This strip which is substantially continuous is fed from a roll through pressure rollers the surfaces of which constitute dies to impress in said strip a plural number of indentions 2 in rows at spaced intervals. Said rows are spaced from each other so that, in its continued passage through the forming machine, the core strip comes in contact with folding dies which depress the portions'of the strip between the rows of said indentions and then these depressed portions are pinched together at the sides of the strip to form double thickness fins 3 extending laterally from the plane of the major portion of the strip.

The strip so formed is then cut into lengths slightly more than twice the dimension of the finished core measured from top to bottom thereof. In other words, if the core as completed is to be about twenty-four inches in height then these strips are cut into lengths of about fifty inches. The purpose of this is to permit these preformed strips to be folded upon themselves as clearly indicated in the drawing, the surplus metal being taken up in the folds 6 at the top and bottom so that when the ends of the strip are brought together and interlocked in the single joint as shown at 9 in Fig. 1 there will be formed a core unit ofa length equal to the height of the finished radiator. Apredetermined number of units are then assembled to form the finished core possessing therequired heat conducting area. Division ,or separator strips may be placed between-the fins of each unit as desired to assist in the radiation of heat as well as to strengthen the core. The fins form portions of the wall structure of the air cells, the remainder of the core unit and the separator strips forming the other walls of said cells. The series of rows ofindentions 2 constitute the tubes 5 to conduct the cooling fluid, such as water, from side to side of the radiator during which travel the heat from said fiuid is abstracted and transferred to the air passing through the air cells. The formation of the radiator core unit strips may be readily understood from the foregoing and with reference to prior issued patents such for example as 1,169,481 granted Jan. 25, 1916 to Herbert G. Harrison for process of making automobile radiator sections. 5 7

Referring to Fig. 1 there is disclosed a radiator core construction in which a fiat strip of very thin metal is employed which has been previously passedthrough forming rolls as above described to impress therein the rows of wedge shaped indentions 2 with folds constituting fins 3 separating the rows of indentions. From Fig. 5 it will be observed that in the formation of the core. strips the side edge portions are crimped as readily understood to provide aseries of serrations or flanges 4 having plane surfaces for the purpose of securing one radiator core unit to its adjacent unit. That is to say, there are provided a plurality of these serrations 4 the surfaces of all of which are angularly disposed creating ridges therebetween, so that when one unit is brought up against an adjacent unit the serrations of the two units will fit and maybe secured together as with solder as clearly shown in Fig. 1 forming a hexagonal joint the coincident indentions of the adjacent units forming the water tubes or passages 5 therebetween. V

Radiator constructions are so. well known that the above will be readily understood by one skilled in the art particularly with refer ence to the drawing, but it might here be stated that these preformed strips are folded back upon themselves creating a fold such as shown at 6 in Fig. 1 and a separator strip as shown at 7 is inserted between the folded over portions of the strip and against which the fins 3 will contactingly rest so that as the heated fluid, such as water, courses down to pass through said spaces and over the surfaces of the metal forming the radiator core.

It is to be observed from Figs. 1, 3 and 1 that the separator strip 7 comprises a plane piece of metal which has been cut and expanded in opposite directions as disclosed in the U. S. Letters Patent #1,220,7t5 granted March 27, 1917 to Herbert G. Harrison and entitled Automobile radiator and that the fins 3 are disposed in staggered relation with each other on opposite sides of said strip. By this construction the indentions 2 are likewise made to assume staggered positions vertically with respect to each other whereby the water in the tube 5 will travel in a zigzag path instead of in a truly vertical path. This is clearly indicated by the arrows in Fi g.

1 and therefore no further description is deemed necessary except to state that by this construction not only is the length ofthe water column increased from the top to the bottom of the core but the water while passing through the tube is subjected to a greater turbulence than in constructions heretofore known, whereby an increased transfer of heat to the metal of the core is accomplished, without unduly restricting the flow through each tube. As a result a higher mean temperature of the metal of the entire core is obtained which insures maximum heat transfer to the air.

Also it is to be observed that the indentions, as clearly seen in Figs- 5 and 6 are substantially wedge shaped in form and of a size maximum to the dimension between the fins 3 whereby practically all the metal between said fins is deflected out of the axial line of the water tube 5 to create the greatest possible degree of deflection of the water column in the core. With reference to Fig. 6 which is a horizontal sectional View of the parts shown in Figs. 1 and 5 it will be seen that should any foreign matter pass over with the cooling fluid from the engine and become wedged in any one of the indentions 2, the continued passage of water is not affected since the following flow will pass to either side of the obincreasing the cooling effect by making the indentions lie instaggered relation with each other and further there is provided means for permitting the water in its flow from the top to the bottom of the core to travel laterally from one vertical pair of indentions to another in a direction from the front to the back of the radiator whereby the maximum cooling effect is had. Also it will be evident from Figure 6 that the air in. passing through the core will contact with the rounded walls of the rows of indentions 2 with, the result. that the air column will be disturbed, broken up, or otherwise afie'cted to create a greater turbulence thereof than if there were no indentions. Therefore there results a greater absorption by the air of the heat from the metal. From actual experiment it has been observed that these indentions 2 should be of a depth maximum to the elasticity of the metal. In other words, the efficiency of the heat transfer increases with the depth of said indentions, and rapidly falls off with a decrease in depth.

In the preceding constructions it should be stated that the pre-crimped strips forming the water tubes as well as the separator strips associated therewith are preferably formed of extremely thin metal, and in practice they r are made of brass as well as copper. Each core unit is formed as above described but it should here be stated that the joint 9 of each is soldered to close one wall of the water tube against leakage. After the parts have been assembled to form the entire radiator core, a clamp is placed around the assembly and pressure applied to hold the parts in tight contacting engagement. The core with the encompassing clamp is then laid in a bath of solder so that the entire surfaces 4:, see Fig. 5, will take up the solder and thus secure the core as a unified mass. The assemblage is then turned over and the other side immersed so that the solder may affect the surfaces 4 of the opposite side of the radiator, all as will be readily understood. The clamp is removed after the solder has cooled and the unified radiator mass placed within its encompassing shell and thus made ready for attachment to the automobile chassis.

In the formation of the core strips and with particular reference to Figs. 2, 5 and 6 it will be seen that the indentions 2 are made of a size maximum to the elasticity of the metal as well as the space between the fins 3.

F In this particular invention it is the purpose to provide a relatively small air cell 8, 'or

an air cell smaller thanthose heretofore contemplated. It'thus results that each indention 2 is relatively shallow with a further result of normally forming a restricted water tube of a thickness less than that shown at 5 in Fig. 2. That is to say, the tube would ordinarily have a small thickness and therefore could easily become squashed or mashed when the core was assembled, or said tube could become easily clogged by a foreign particle in the water flow during the function ing of the radiator.

Therefore by this invention the small air cell area is retained while overcoming the above stateddefects. This is done by sub j ecting the sides of the core strip to a further pressure during its formation suficient to slightly reduce the thickness of the metal at the place of application as clearly indicated at 15 in Fig. 7, whereby the surface area of the metal along each side is increased.

In other wordseach. edge portion of the core strip in the serrations or flanges 4.- is expand ed so that when the adjacent units are assembled there will be a space 13 between the expanded portion 15 and the first vertical row of indentions 2 as clearly seen from Fig. 2. This results in an enlargement of the thickness of the water tube, now indicated by the numeral 5 in Fig. 2, whereby an increased flow of the cooling fluid through said tube is accomplished. As a result the likelihood of an obstruction lodging in the tube is circumvented but should the tube become clogged at a particular point, the cooling fluid may readily pass laterally around or to one side of said obstruction and thus pass through the core.

Intermediate the sideextremities of the core strips are formed projections 18 constituting abutments which, as clearly indicated in Fig. 6, separate one water tube 5 from another. Also these projections are somewhat wedge shaped so that, when the core strip isbent around as before stated to form the core unit, the opposing projections will interfit but they are not soldered nor do they so tightly fit that they form an impassable barrier between the water tubes.

It is obvious that'those skilled in theart may vary the details of construction and arrangements of parts without departing from the spirit of theinvention and there Nil adepressedportion extending inwardly of the unit between said edge portions to form one-half of a water tube extending from top to bottom of said unit, the outer face of said tube lying in a plane parallel to the plane of the'ridges, the metal of the serrated edge portion being of a thickness less than the metal of the rest of the wall and the angle of said thinned edge portions'being such that the ridges of said serrations are disposed farther from the plane of the tube face than would be the case if the metal were all of the same thickness, as a result of which when two similarly formed units are joined together .rith their serrated edge portions interfitting the complete water tube formed thereby will have an increased dimension.

2. The herein described radiator unit, the same comprising outer walls each provided with a plurality of cooling fins, the extreme edge portions of each wall between the fins having serrations providing a plurality of outwardly extending ridges lying in a common vertical plane, said'wall provided with a depressed portion extending inwardly of the unit between said edge portions to form onehalf of a water'tube extending from top to bottom of said unit, the outer face of said tube lying in aplane parallel to the plane of the ridges, the thickness of the metal of the serrated edge portion being different from the metal of the rest of the wall, and the angle of said edge portions being such that the ridges of said serrations are disposed farther from the plane of the tube face than would be the case if the metal were all of the same thickness, as a result of which when two similarly formed units are joined together with their serrated edge portions interfitting thecomplete water tube formed thereby will have an increased dimension.

3. The herein described radiator unit, the same comprising a wall of sheet metal having a plurality of spaced cooling fins extending in one direction therefrom, serrations between said fins along the edge portions of said wall and extending in the opposite di- 7 rection therefrom, said serrations forming ridges between said finslying in a common vertical plane parallel to the plane of the outer edges of said fins, the metal of the serrations being of a thickness different from the thickness ofthe metal of the rest of said wall so that the angles of said serrations are such that said ridges lie farther from" the plane of said fin edges than they would if the serrations were of the same thickness as the rest of the wall. y

4. The herein described radiator unit, the same comprising a wall of sheet metal,ser-' rations along opposite side edge portions of said wall, said serrations forming ridges lying in a common vertical plane parallel to the plane of said wall, the metal of the serrations being of a thickness different from the thickness of the metal of the rest of said wall so that the angle of said serrations are such that said ridges lie farther from the plane of said wall than they would if the serrations we? of the same thickness as the rest of the wa 5. The herein described radiator unit, the same comprising a wall of sheet metal having a plurality of spaced cooling fins extending in one direction therefrom, serrations between said fins along the edge portions of said wall and extending inthe opposite direction therefrom, said serrations forming ridges between said fins lying in a common vertical plane parallel to the plane of the outer edges of said fins, the metal of the serrations being of a thickness different from the thickness of the metal of said wall between said edge portions so that said ridges lie farther from the plane of said fin edges than they would if the serrations were of the same thickness as the rest of the wall.

In testimony whereof I affix my signature.

WELLINGTON W. MUIR. 

